The present invention relates to a radiation treatment apparatus according to the preamble of Claims 1 and 6.
Such radiation treatment apparatus are used, in particular, in medical radiotherapy, especially, for instance, for the treatment of tumors. There so-called applicators, i.e. thin hollow needles or plastic flanges are implanted as hollow probes into the target object (the tumor). A radiator holder, for instance a wound spring with spacers and one or more radiation-active zones, is then brought into the hollow probe and thus to the place of treatment (afterloading). When the radiators are not used they must be stored in a radiation shielding container. During the transfer of the radiators from the radiation shielding container into the hollow probe, the operator is exposed to the--even though not excessively strong--radioactive radiation of the radiators. This disadvantage upon the manual insertion of the radiation holder into the hollow probe has been eliminated in an automatically operating afterloading device of the aforementioned type in which the radiation shielding container receives a single radiation holder which, by means of a tube channel switch on the outlet side of the radiation shielding container can be brought into and out of a predeterminable hose which is connected for through-passage with the hollow probe.
This known radiation treatment apparatus has the disadvantage that one can use only a single radiator holder with a single source of radiation present on it and which must be moved within the hollow probe from place of treatment to place of treatment and, after the end of the treatment, moved back within this hollow probe into the radiation shielding container and then, after displacing the hose channel switch, brought into the next hollow probe. This mandatory manner of procedure results in a very long period of treatment during which the object or patient to be treated must be connected to the radiation treatment apparatus. In particular, it is not possible to insert different radiation holders so that two or more predeterminably spaced radiators could be used as necessary on one radiation holder within the individual hollow probes. As a rule, namely, a different number of differently spaced radiation points must be established in the different hollow probes at the place of treatment.
From U.S. Pat. No. 3,861,380 a radiation treatment apparatus of the aforementioned type is known in which a separate drive device is necessary for the insertion and removal of each individual radiator holder--the other radiators therefore remaining in the radiation shielding container; this manner of procedure is possible only with independent drives for the individual radiator holders. In this known radiation treatment apparatus the protection from radiation required for the operating personnel and the patients can of course only be assured if a functional testing of the apparatus without radiators is carried out before each radiation treatment. It is clear that the separate drives of the individual radiators take up a considerable amount of space, so that this known radiation treatment apparatus can be equipped only with comparatively few individually operating radiators (the apparatus must, after all, remain sufficiently small to be portable so that the said test-runs can be carried out in the spaces intended for this).